diff --git a/java/monasca-common-model/src/main/resources/monasca/common/model/alarm/AlarmExpression.g4 b/java/monasca-common-model/src/main/resources/monasca/common/model/alarm/AlarmExpression.g4
index ade3f3a9..e5655132 100644
--- a/java/monasca-common-model/src/main/resources/monasca/common/model/alarm/AlarmExpression.g4
+++ b/java/monasca-common-model/src/main/resources/monasca/common/model/alarm/AlarmExpression.g4
@@ -138,6 +138,7 @@ txt
     : TXT
     | keyword
     | INTEGER
+    | DECIMAL
     | STRING
     ;